Code 18 on 1993 Buick Regal - Page 2 - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Buick When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 03-18-2015, 02:24 AM   #11
Junior Member
Posts like a V-Tak
Thread Starter
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

I did a pretty extensive wire check too btw and found the sensor wire to the alternator had a bare spot so i wrapped some wire around it and put everything back together and it still ran like crap. I'm not sure if its worth sticking the old ecm in it or checking that wire some more.

I'll definitely take another look at those coils though and see if there'* something I'm missing. Can a coil be bad if the resistance checks out or would it be a ICM problem or ground problem?
swl2001 is offline   Reply With Quote
Old 03-18-2015, 11:02 AM   #12
Senior Member
Posts like a Turbo
 
Join Date: Nov 2011
Posts: 407
Thanked 18 Times in 14 Posts
Kimberly will become famous soon enoughKimberly will become famous soon enough
Default

Ohm checks with coils can help but the problem is probably not that the coil is completely dead but weak. The best way to test a coil would be to connect an ignition wire to the coil, a good spark plug with the proper gap to the wire and then pulse the coil like the ignition module would and visually observe the spark at the plug *unless you have a high voltage probe; I don't know what the primary voltage is to the coils; perhaps someone else could say.

From what I understand on this year model is that a misfire is causing the Code 18 to set even though Code 18 is for something else. This year does not have a misfire indication for the computer but a misfire can trip the Code 18. If you have put in good wires and plugs then I would suspect the coils as the source of the code 18. I had even replaced the Ignition Control Module on my car.

If this was my car, I would go to Ebay and find the cheapest set of coils (check the shipping fees as some will be cheap but high shipping) and replace them. That is what I did because I didn't have the money and needed to have a car; kind of hard to walk 18 miles to work. It may not be the coils, could be something else but the mechanic in Ca told me he had a 93 Buick with Code 18 he traced it to a bad coil and it was the same for my car. So that is two different ones that had Code 18 on a 93 Buick due to a bad coil.

Yes, have it dark as it may not be a strong arch, you may just see some stray voltage. When I got the Code 19 a few weeks after fixing the Code 18; which was not due to what the official GM shop manual stated, I looked at the engine in the dark and noticed that the number one wire had stray voltage that would travel the length of the wire, you could see it. No arcing, just sort of crawling along the wire. In the daytime it was not possible to see it. The wires I had on the car were only two years old but I had brought a cheap pair due to no money woes. I got a mid-grade set of wires and replaced them and the Code 19 went away and the car ran fine.
Kimberly is offline   Reply With Quote
The Following 2 Users Say Thank You to Kimberly For This Useful Post:
swl2001 (03-19-2015), WilliamE (03-19-2015)
Old 03-18-2015, 11:03 AM   #13
Senior Member
Posts like a Turbo
 
Join Date: Nov 2011
Posts: 407
Thanked 18 Times in 14 Posts
Kimberly will become famous soon enoughKimberly will become famous soon enough
Default

I know it is hard to throw parts at a car to fix it. I did that as well. I suggest the cheap coils because if you don't have the money to throw parts at it then we have to go cheap to see. However, if you can afford it, get the good coils.
Kimberly is offline   Reply With Quote
Old 03-19-2015, 12:33 AM   #14
Junior Member
Posts like a V-Tak
Thread Starter
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

I finally got a chance to look at the car in the dark and observed some arcing at terminal 1 between the plug wire terminal and the center part of the coil (with wire connected to Coil). Would this indicate a bad wire or bad ignition coil? I did see a bit of black on the inside of the spark plug wire where it contacts. I rotated it and there was less noticeable arcing but still some there (went from orange to blue)
swl2001 is offline   Reply With Quote
Old 03-19-2015, 01:00 AM   #15
Senior Member
Posts like a Turbo
 
Join Date: Nov 2011
Posts: 407
Thanked 18 Times in 14 Posts
Kimberly will become famous soon enoughKimberly will become famous soon enough
Default

If you have a wire to replace that one with you could check if changing the wire makes a difference. You could also swap that coil with another, they are all the same, and see if the problem moves with the coil (all coils in place of course). They are easy to swap out, remove the boilts and they just unplug from the ignition module. If the arcing follows the coil; with the wires not moved, then you know the coil is bad, just replace that one coil if you wish without replacing the others.
Kimberly is offline   Reply With Quote
Old 03-19-2015, 01:13 AM   #16
Junior Member
Posts like a V-Tak
Thread Starter
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

I switched the arcing wire to another coil and it continued to arc. I unfortunately threw out the old wires so I'm picking a new set up now. Fingers crossed
swl2001 is offline   Reply With Quote
Old 03-19-2015, 01:24 AM   #17
Senior Member
Posts like a Turbo
 
Join Date: Nov 2011
Posts: 407
Thanked 18 Times in 14 Posts
Kimberly will become famous soon enoughKimberly will become famous soon enough
Default

OK, you may have found your problem. I would go with a good set, maybe not the most expensive but not the cheapest either.
Kimberly is offline   Reply With Quote
Old 03-19-2015, 03:11 AM   #18
Junior Member
Posts like a V-Tak
Thread Starter
 
Join Date: Mar 2015
Posts: 27
Thanked 2 Times in 2 Posts
swl2001 is on a distinguished road
Default

IT WORKS!!!

Never in my life did I think a single bad wire could mess up how the car runs so much. I ended up swapping out the front 3 wires and I'll probably get the back ones later. I knew the Buick still had some life in it. I drove it 2400 miles from Michigan to California last summer with no problems so I knew it had to be something stupid like a plug wire.

I admittedly went with the cheapest set at o'reilly'* for $20 but they have a lifetime warranty and were made in the US so hopefully they'll do (Last ones were from Mexico). Thanks for your help because the first good car that popped up on craigslist I was getting it.

RECAP FOR GOOGLE SEARCH FOLK:
If you have a code 18 check the coils or arcing on spark plug. Don't waste your time on the Crankshaft Sensor of Camshaft Sensor (I believe they have separate codes on the 93 anyways)
swl2001 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
2002 Buick Regal with P1811 code regalfuts Buick 3 03-20-2013 09:46 AM
98 Buick Regal GS Code P0303 Misfire HELP! Rawben Buick 22 09-20-2011 08:09 AM
Cranks but No Spark, 1993 regal daveyb56 1992-1999 4 05-28-2011 10:48 AM
1991 SSE - code 28 code 39 code 42 - losing sleep labonnita 1987-1991 9 12-26-2009 10:58 PM
Buick Regal Replacement.. Custom88 Lounge 8 01-28-2004 10:17 PM


Tags
3.8, 3.8l, 3800, buick regal, code 18

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 08:19 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.